The use of ferromagnetic materials for structuring chip components comprising both inductors and capacitors has previously been limited by the difficulty in using ferromagnetic materials in connection with dielectric materials. The inductors are often made of a ferrite and are used by way of known printing methods for structuring layer structures including internal conducting paths. These inductors have low inductances due to the low permeability of the ferromagnetic material. EP-PS No. 297 565 discloses for instance a ferromagnetic material of relatively low permeability caused by a very small granular size and a high content of glass. Attempts have be made to obtaining a higher permeability by raising the sintering temperature or increasing a sintering period, but from a productional point of view such procedures are disadvantageous or necessitate the use of cost-intensive electrode materials, such a Pd. Thus the material described in EO-PS No. 297 565 requires a sintering period of 30-220 min., which makes a production under usual thick-film conditions difficult. Furthermore, the final components have a relatively poor mechanical strength.
Moreover chip components comprising both inductors and capacitors suffer from delamination and distortion at the interface zone between the ferromagnetic and the dielectric zones. Chip components comprising both inductors and capacitors are furthermore encumbered with problems due to reactions at the interface between the ferromagnetic and the dielectric zones, whereby the characteristics of these materials are deteriorated.
These problems can be set right by the ferromagnetic zones being separated from the dielectric zones of the capacitors by means of a blocking layer, cf. Danish Patent Application No. 908/91.